A novel approach for broken-rotor-bar detection in cage induction motors

In this paper, a new approach is proposed to detect broken rotor bars in induction motors. The motor is disconnected from the supply, and the induced voltage in the stator due to only rotor flux is utilized to detect the fault. If there is any broken bar, it will directly affect the induced voltages in the stator windings. Using this approach, the effects of source nonidealities (such as unbalance, presence of time harmonics, etc.) and nonlinearity of machine magnetizing characteristics due to saturation can be avoided.